scholarly journals Performance and Emission Characteristics of Homogeneous Charge Compression Ignition Engine with Different Bio Diesel Fuels

2018 ◽  
Vol 7 (4.24) ◽  
pp. 157 ◽  
Author(s):  
P Moulali ◽  
T H Prasad ◽  
B D Prasad
Keyword(s):  
Homogeneous Charge Compression Ignition ◽  
Fuel Injection ◽  
Emission Characteristics ◽  
Compression Ignition ◽  
Compression Ignition Engine ◽  
Hcci Engine ◽  
Diesel Fuels ◽  
Port Fuel Injection ◽  
Mixture Preparation ◽  
Algae Oil

In this paper the emission characteristics and performance of various bio diesel fuels (Tyre pyrolysis oil (TPO), Micro algae oil and Pig animal fat oil) were experimented. A single cylinder, water cooled diesel engine was modified in to homogeneous charge compression ignition engine (HCCI) with adopted port fuel injection (PFI) technique. The effects of air fuel ratio, intake temperature, injection pressure and EGR rate exhaust emissions were explained in a broad manner. The analysis of the exhaust emissions are integrated to oxides of Nitrogen (NOx), Carbon Monoxide (CO), unburned hydro carbons (UHC), smoke and soot. The performance analysis was also included on specific fuel consumption and break thermal efficiency. The basic requirements for HCCI engine is the homogeneous mixture preparation of air and fuel. This mixture formation was done by adopting port fuel injection technique and external devices were also used for bio diesel vaporization and mixture preparation. The combustion processes were measured with different EGR system.  The experimental results of different bio diesel fuels with HCCI engine mode were recorded and evaluated. A small increase in CO and HC emissions were observed with increasing bio diesel content due to slow evaporation rate of bio diesel. A significant reduction in NOx emission was also observed with respect to difference in bio diesel blends. Micro algae oil was found more stable compared with other bio diesel fuels due to the property of fuel vaporization and low heat releasing.

Combustion and emission characteristics of a homogeneous charge compression ignition engine

2005 ◽  
Vol 219 (9) ◽  
pp. 1133-1139 ◽  
Author(s):  
Hu Tiegang ◽  
Liu Shenghua ◽  
Zhou Longbao ◽  
Zhu Chi
Keyword(s):  
Heat Release ◽  
Homogeneous Charge Compression Ignition ◽  
Cetane Number ◽  
Pressure Rise ◽  
Operating Conditions ◽  
Emission Characteristics ◽  
Compression Ignition ◽  
Compression Ignition Engine ◽  
Hcci Engine ◽  
Homogeneous Charge

Dimethyl ether (DME) is a kind of fuel with high cetane number and low evaporating temperature, which is suitable for a homogeneous charge compression ignition (HCCI) engine. The combustion and emission characteristics of an HCCI engine fuelled with DME were investigated on a modified single-cylinder engine. The experimental results indicate that the HCCI engine combustion is a two-stage heat release process. The engine load or air-fuel ratio has significant effects on the maximum cylinder pressure and its position, the shape of the pressure rise rate and the heat release rate. The engine speed has little effect. A DME HCCI engine is smoke free, with zero NOx and low hydrocarbon and CO emissions under the operating conditions of 0.25–0.30 MPa brake mean effective pressure.

scholarly journals Effect of port injection pressure on mixture quality in Homogeneous charges compression ignition (HCCI) engine

2021 ◽  
Vol 9 (2) ◽  
pp. 37-41
Keyword(s):  
Diesel Engine ◽  
Fuel Injection ◽  
Injection Pressure ◽  
The Other ◽  
Emission Characteristics ◽  
Compression Ignition ◽  
Fuel Injector ◽  
Compression Ignition Engine ◽  
Hcci Engine ◽  
Fuel Injection Pressure

The purpose of this study is to investigate the effect of fuelinjection pressure onhomogeneous charge formation and performanceand emission characteristics of Homogeneous charge compression ignition engine. The fuel injection pressure isone of the primary parameter for improvingthe homogeneity of the mixture and governing the power output and emission characteristics of HCCI engine. In this investigation, diesel fuelwasinjected at different injection pressuresas 2bar, 3bar, 4bar and 5bar respectively throughbyport fuel injector. The experimental investigationsshow that increasing the fuel injection pressure will promote the fuel to penetrate with air and creates well pre mixedair/fuel charge.The result shows, the specific fuel consumption (SFC) of HCCI engine isslightlyhigherthan the SFC of conventional diesel engine.The HCCI engine with 3bar injection pressure operated engine has lower SFC values compared to other injection pressure operated HCCI engine.The brake thermal efficiency of HCCI engine, operated with 3barinjection pressure has maximum BTE values over the other injection pressure operated engine.From theresult, it is observed that HCCI engine has lower smoke density values compared to conventional diesel engine andfurther reducedby increasing the fuel injection pressure. The 3bar injection pressure operated HCCI engine has emitted lower smoke densitycompared to other injection pressure operated HCCI engine. The 3bar injection pressureoperated HCCIengine hasemittedmaximum oxides of nitrogen (NOx) emissions than the other injection pressure operated HCCI engine. Other exhaust emissions of carbon monoxide (CO) and hydrocarbon (HC)emissions are increased when compared toconvention diesel engine

scholarly journals Influence of gas composition on the combustion and efficiency of a homogeneous charge compression ignition engine system fuelled with methanol reformed gases

2008 ◽  
Vol 9 (5) ◽  
pp. 399-408 ◽  
Author(s):  
T Shudo
Keyword(s):  
Homogeneous Charge Compression Ignition ◽  
Waste Heat ◽  
Compression Ignition ◽  
Compression Ignition Engine ◽  
Temperature Oxidation ◽  
Hcci Engine ◽  
Recovery Capacity ◽  
Exhaust Heat ◽  
Engine System ◽  
Homogeneous Charge

A homogeneous charge compression ignition (HCCI) engine system fuelled with dimethyl ether (DME) and methanol-reformed gas (MRG), both produced from methanol by onboard reformers using exhaust heat, has been proposed in previous research. Adjusting the proportions of DME and MRG with different ignition properties effectively controlled the ignition timing and load in HCCI combustion. The use of the single liquid fuel, methanol, also eliminates the inconvenience of carrying two fuels while maintaining the effective ignition control effect. Because reactions producing DME and MRG from methanol are endothermic, a part of the exhaust gas heat energy can be recovered during the fuel reforming. Methanol can be reformed into various compositions of hydrogen, carbon monoxide, and carbon dioxide. The present paper aims to establish the optimum MRG composition for the system in terms of ignition control and overall efficiency. The results show that an increased hydrogen fraction in MRG retards the onset of high-temperature oxidation and permits operation with higher equivalence ratios. However, the MRG composition affects the engine efficiency only a little, and the MRG produced by the thermal decomposition having the best waste-heat recovery capacity brings the highest overall thermal efficiency in the HCCI engine system fuelled with DME and MRG.

Experimental and Numerical Analysis on the Influences of Direct Fuel Injection into Oxygen-Depleted Environment of a Homogeneous Charge Compression Ignition Engine

2021 ◽  
pp. 1-29
Author(s):  
Ratnak Sok ◽  
Kei Yoshimura ◽  
Kenjiro Nakama ◽  
Jin Kusaka
Keyword(s):  
Homogeneous Charge Compression Ignition ◽  
Fuel Injection ◽  
Double Pulse ◽  
Gasoline Direct Injection ◽  
Oh Radicals ◽  
Compression Ignition ◽  
Compression Ignition Engine ◽  
Intake Stroke ◽  
Direct Fuel Injection ◽  
Homogeneous Charge

Abstract The oxygen-depleted environment in the recompression stroke can convert gasoline fuel into light hydrocarbons due to thermal cracking, partial oxidation, and water-gas shift reactions. These reformate species can influence the combustion characteristics of gasoline direct injection homogeneous charge compression ignition (GDI-HCCI) engines. In this work, the combustion phenomena are investigated using a single-cylinder research engine under a medium load. The main combustion phases are experimentally advanced by direct fuel injection into the negative valve overlap (NVO) compared with that of intake stroke under single/double pulse injections. NVO peak in-cylinder pressures are lower than that of motoring due to the limited O2 concentration, emphasizing that endothermic reactions occur during the overlap. This phenomenon limits the oxidation reactions, and the thermal effect is not pronounced. The 0-D chemical kinetics results present the same increasing tendencies of classical reformed species of rich-mixture such as C3H6, C2H4, CH4, CO, and H2 as functions of injection timings. Predicted ignition delays are shortened due to the additions of these reformed species. The influences of the reformates on the main combustion are confirmed by 3-D CFD calculations, and the results show that OH radicals are advanced under NVO injections relative to intake stroke injections. Consequently, earlier heat release and cylinder pressure are noticeable. Parametric studies on the effects of injection pressure, double-pulse injection, and equivalence ratio on the combustion and emissions are also discussed experimentally.

Computational fluid dynamics simulation of in-cylinder flows in a motored homogeneous charge compression ignition engine cylinder with variable negative valve overlapping

2007 ◽  
Vol 221 (10) ◽  
pp. 1295-1304 ◽  
Author(s):  
A-F M Mahrous ◽  
M L Wyszynski ◽  
T Wilson ◽  
H-M Xu
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Homogeneous Charge Compression Ignition ◽  
Compression Ignition ◽  
Hcci Engine ◽  
Mixture Preparation ◽  
Engine Cylinder ◽  
The Times ◽  
Exhaust Valves ◽  
Predictive Study

In-cylinder air motion is one of the most important factors that control the degree of mixture preparation and thus is fundamental to improvements in the combustion process and overall engine performance. The major aim of this paper is to elucidate, through a predictive study, the main features of in-cylinder flow fields in a motored homogeneous charge compression ignition (HCCI) engine cylinder with variable negative valve overlapping (NVO). A commercial finite-volume computational fluid dynamics (CFD) package was used in the programme of simulation. The computational model was validated through a qualitative comparison between CFD results and the available experimental data. Thus one of the main developments presented in this study is the investigation of the intake process of the HCCI engine with various valve strategies, and it is perhaps the first time (to the current authors' best knowledge) that a direct comparison has been made of the results obtained in the same HCCI NVO motored engine using modelling and experimental approaches. The comparison illustrated a fair agreement between both sets of results, with some differences. A parametric predictive study of the effects of variable valve timings on the in-cylinder air motion has then been carried out. Three different sets of valve timings have been applied to the intake and exhaust valves to generate NVO of 70, 90, and 110 degrees of crank angle (°CA). The NVO was controlled by adjusting the times of exhaust valves closing (EVC) and intake valves opening (IVO) while keeping the times of exhaust valves opening (EVO) and intake valves closing (IVC) unchanged. The predicted results show a noticeable modification of the strength and the global direction of the in-cylinder charge motion as a result of increasing the magnitude of NVO. Modifications of in-cylinder swirl and tumble motions obtained by applying higher degrees of NVO are expected to have a considerable effect on the air-fuel mixture preparation process as well as the actual in-cylinder conditions at the end of the compression stroke.

scholarly journals Effect of Preheating Temperature and Fuel Properties on Combustion and Emission Characteristics of Homogeneous Charge Compression Ignition (HCCI) Engine

2021 ◽  
Vol 9 (5) ◽  
pp. 558-564
Keyword(s):  
Experimental Investigation ◽  
Diesel Engine ◽  
Air Temperature ◽  
Homogeneous Charge Compression Ignition ◽  
Fuel Properties ◽  
Emission Characteristics ◽  
Compression Ignition ◽  
Hcci Engine ◽  
Di Diesel Engine ◽  
Homogeneous Charge

The homogeneous charge compression ignition (HCCI) engine is the promising technology to reduce the pollutants without affecting its performance and it is also proved by the many studies. This study investigates the performance and emission characteristics of HCCI engine fuelled with diesel –waste cooking oil (WCO) blends and also analysed the effect of air temperature and fuel properties on HCCI engine combustion. The experimental investigation was conducted with single cylinder DI diesel engine and it was slightly modified to port injection system for premixing the charge. The electric air heater was adopted in suction pipe to preheat the inlet air. The experimental investigation conducted in two phases, in the first phase the conventional DI diesel engine was tested with different fuel blends such as B25, B50, B75 and B100 and notes the readings. In the next phase, HCCI engine was operated with same blend ratios. During the experimentation on HCCI engine, the suction air temperature was varied between 40⁰C to 90⁰C. From the experimental results, it was found that the HCCI engine has emitted low NOx and smoke emissions at 80⁰C of air temperature for all the blends. Whereas the HCCI engine emitted more carbon monoxide (CO) and hydrocarbon (HC) emissions due to lean mixture causes misfiring in the chamber. In addition, it is also noted that the value of CO and HC has been varied with diesel –WCO blends. The specific fuel consumption (SFC) is increased for diesel and biodiesel fuel in HCCI engine compared to compression ignition (CI) engine

Modelling and Simulation of Homogeneous Charge Compression Ignition Engine Fueled by Biodiesel

2018 ◽  
Author(s):  
Meshack Hawi ◽  
Mahmoud Ahmed ◽  
Shinichi Ookawara
Keyword(s):  
Heat Release ◽  
Compression Ratio ◽  
Homogeneous Charge Compression Ignition ◽  
Internal Combustion ◽  
Operating Conditions ◽  
Emission Characteristics ◽  
Compression Ignition ◽  
Hcci Engine ◽  
Hcci Engines ◽  
Homogeneous Charge

Homogeneous charge compression ignition (HCCI) is a combustion technology which has received increased attention of researchers in the combustion field for its potential in achieving low oxides of nitrogen (NOx) and soot emission in internal combustion (IC) engines. HCCI engines have advantages of higher thermal efficiency and reduced emissions in comparison to conventional internal combustion engines. In HCCI engines, ignition is controlled by the chemical kinetics, which leads to significant variation in ignition time with changes in the operating conditions. This variation limits the practical range of operation of the engine. Additionally, since HCCI engine operation combines the operating principles of both spark ignition (SI) and compression ignition (CI) engines, HCCI engine parameters such as compression ratio and injection timing may vary significantly depending on operating conditions, including the type of fuel used. As such, considerable research efforts have been focused on establishing optimal conditions for HCCI operation with both conventional and alternative fuels. In this study, numerical simulation is used to investigate the effect of compression ratio on combustion and emission characteristics of an HCCI engine fueled by pure biodiesel. Using a zero-dimensional (0-D) reactor model and a detailed reaction mechanism for biodiesel, the influence of compression ratio on the combustion and emission characteristics are studied in Chemkin-Pro. Simulation results are validated with available experimental data in terms of incylinder pressure and heat release rate to demonstrate the accuracy of the simulation model in predicting the performance of the actual engine. Analysis shows that an increase in compression ratio leads to advanced and higher peak incylinder pressure. The results also reveal that an increase in compression ratio produces advanced ignition and increased heat release rates for biodiesel combustion. Emission of NOx is observed to increase with increase in compression ratio while the effect of compression ratio on emissions of CO, CO2 and unburned hydrocarbon (UHC) is only marginal.

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